The driver and other occupants of motor vehicles experience various driving stresses during the course of a typical drive. Such stress to the body may also include stress to the spine which often causes discomfort and which may cause injury in extreme situations.
The occupants of vehicles may be forced in a lateral direction with respect to their seat, for example, during a vehicle collision or during a sharp turn. The occupants may be thrown against other occupants of the vehicle or the inner side walls of the vehicle. When the driver of the vehicle experiences such forces, he may lose control of the vehicle.
If the backrest portion and/or the seating portion of the vehicle seat are each provided with a pair of lateral bolsters or bolster sections, lateral movement of the occupant of the vehicle seat is more restricted to protect the occupant of the seat. Such a backrest portion of a vehicle seat is disclosed in the Faust U.S. Pat. No. 3,627,379.
The protective quality of vehicle seats having lateral bolster sections is largely determined by how snugly the side bolster sections are laterally positioned about the occupant of the vehicle seat. It is desirable that the distance between such bolster sections be slightly greater than the width of the occupant of the seat. While such snugness is desirable for safety reasons, a certain amount of looseness is also important for the comfort of the occupant. Also such looseness allows the driver the necessary freedom of movement to drive the vehicle.
One possible, yet impractical, solution for providing such lateral support with comfort is to have each vehicle seat custom made to fit each occupant. Such a seat would be expensive and would invariably fail to accommodate others. Also, depending on the amount of clothing worn by the occupant, the seat may at times be unsuitable for an occupant for whom the seat was designed. Obviously, the optimum difference in distance between the bolster section varies depending on the effective width of the occupant.
Consequently, it is desirable that the effective distance between such bolster sections be variable to provide the necessary support and comfort for the particular occupant of the vehicle seat. One known method is to adjust the lateral position of each bolster section by a handwheel which, upon rotation, causes the associated bolster section to move relative to its associated backrest portion. In this way, the distance between the adjusted bolster section and the bolster section mounted at the opposite side of the backrest portion is varied. The other bolster section may be individually adjusted by its own handwheel in a similar fashion.
Such a method for varying the distance between a pair of corresponding bolster sections is not only complicated but also time-consuming in that each of the bolster sections must be individually adjusted to obtain the proper distance therebetween. Furthermore, once the proper distance is obtained, it is possible that one of the bolster sections may be angled to a greater or lesser extent with respect to its corresponding backrest or seating portion than those bolster sections thereby causing discomfort to the occupant of the seat.
Vehicle seats generally of the type to which this invention relates are disclosed by Goldner U.S. Pat. No. 4,169,899, Tischler U.S. Pat. No. 3,727,890 and Capener et al U.S. Pat. No. 3,623,768.